An estimated 4 to 5 million Americans (about 2% of all ages and 15% of those older than age 65) have some form and degree of cognitive failure. Cognitive failure (dysfunction or loss of cognitive functions, the process by which knowledge is acquired, retained and used) commonly occurs in association with central nervous system (CNS) disorders or conditions, including age-associated memory impairment, delirium (sometimes called acute confusional state), dementia (sometimes classified as Alzheimer's or non-Alzheimer's type), Alzheimer's disease, Parkinson's disease, Huntington's disease (chorea), mental retardation, cerebrovascular disease (e.g., stroke, ischemia), affective disorders (e.g., depression), psychotic disorders (e.g., schizophrenia, autism (Kanner's Syndrome)), neurotic disorders (e.g., anxiety, obsessive-compulsive disorder), attention deficit disorder (ADD), subdural hematoma, normal-pressure hydrocephalus, brain tumor, head or brain trauma.
Cognitive dysfunction is typically manifested by one or more cognitive deficits, which include memory impairment (impaired ability to learn new information or to recall previously learned information), aphasia (language/speech disturbance), apraxia (impaired ability to carry out motor activities despite intact motor function), agnosia (failure to recognize or identify objects despite intact sensory function), disturbance in executive functioning (i.e., planning, organizing, sequencing, abstracting).
Cognitive dysfunction causes significant impairment of social and/or occupational functioning, which can interfere with the ability of an individual to perform activities of daily living and greatly impact the autonomy and quality of life of the individual.
Cognitive training protocols are generally employed in rehabilitating individuals who have some form and degree of cognitive dysfunction. For example, cognitive training protocols are commonly employed in stroke rehabilitation and in age-related memory loss rehabilitation. Because multiple training sessions are often required before an improvement or enhancement of a specific aspect of cognitive performance (ability or function) is obtained in the individuals, cognitive training protocols are often very costly and time-consuming.